QtDataVisualization's OptimizationStatic was only supported for Scatter3D, but instancing works in a different way and is usable for Bars3D too (perhaps Surface3D as well?).

We should:

• make instanced rendering the OptimizationDefault for all graphs
• add a new optimization for the old style, which is currently OptimizationDefault (OptimizationLegacy, or something)
• recreate OptimizationStatic the same way it was done for QtDataVisualization (if sensible - tests need to be done)